Endoscopic ultrasonography (EUS) allows your doctor to examine your esophageal and stomach linings as well as the walls of your upper and lower gastrointestinal tract. The upper tract consists of the esophagus, stomach and duodenum while the lower tract includes your colon and rectum. EUS is also used to study other organs that are near the gastrointestinal tract, including the lungs, liver, gall bladder and pancreas.
Your endoscopist will use a thin, flexible tube called an endoscope that has a built-in miniature ultrasound probe. Your doctor will pass the endoscope through your mouth or anus to the area to be examined. Your doctor then will use the sound waves to create visual images of the digestive tract.
Why is EUS done?
EUS provides your doctor with more information than other imaging tests by providing detailed images of your digestive tract. Your doctor can use EUS to diagnose certain conditions that may cause abdominal pain or abnormal weight loss.
EUS is also used to evaluate known abnormalities, including lumps or lesions, which were detected at a prior endoscopy or were seen on x-ray tests, such as a computed tomography (CT) scan. EUS provides a detailed image of the lump or lesion, which can help your doctor determine its origin and help treatment decisions. EUS can be used to diagnose diseases of the pancreas, bile duct and gallbladder when other tests are inconclusive or conflicting.
Why is EUS used for patients with cancer?
EUS helps your doctor determine the extent of spread of certain cancers of the digestive and respiratory systems. EUS allows your doctor to accurately assess the cancer’s depth and whether it has spread to adjacent lymph glands or nearby vital structures, such as major blood vessels. In some patients, EUS can be used to obtain a needle biopsy of a lump or lesion to help your doctor determine the proper treatment.
How should I prepare for EUS?
For EUS of the upper gastrointestinal tract, you should have nothing to eat or drink, usually for eight hours before the examination. Your doctor will tell you when to start this fasting and whether it is advisable to take your regular prescription medications.
For EUS of the rectum or colon, your doctor will instruct you to either consume a colonic cleansing solution or to follow a clear liquid diet combined with laxatives or enemas prior to the examination.
What about my current medications or allergies?
You can take most medications as usual until the day of the EUS examination. Tell your doctor about all medications that you’re taking and about any allergies you have. Anticoagulant medications (blood thinners such as warfarin or heparin) and clopidogrel may need to be adjusted before the procedure. Insulin also needs to be adjusted on the day of EUS. In general, you can safely take aspirin and non-steroidal anti-inflammatory medications (ibuprofen, naproxen, etc.) before an EUS examination. Check with your doctor in advance regarding these recommendations.
Check with your doctor about which medications you should take the morning of the EUS examination, and take only essential medications with a small sip of water.
Do I need to take antibiotics?
Antibiotics are not generally required before or after EUS examinations. However, your doctor might prescribe antibiotics if you are having specialized EUS procedures, such as to drain a fluid collection or a cyst using EUS guidance.
Should I arrange for help after the examination?
If you received sedatives, you will not be allowed to drive after the procedure, even if you do not feel tired. You should arrange a ride home in advance. You should also plan to have someone stay with you at home after the examination, because the sedatives could affect your judgment and reflexes for the rest of the day.
Can I take my current medications?
Most medications can be continued as usual. Inform your physician of medications you’re taking, particularly aspirin products, arthritis medications, anticoagulants (blood thinners), insulin or iron products. Use of medication will be directed by your physician.
What if I use inhalers for asthma or other breathing problems?
Please use your inhalers as you would normally use them. Also, please be sure and bring all of your inhalers to your procedure, as you may be asked to use them just prior to your exam.
Will I need antibiotics?
Possibly. This will depend on the specific circumstances of why you are having the EUS done. Your physician will discuss antibiotics with you prior to scheduling your procedure.
What can I expect during EUS?
EUS is well tolerated and pain-free. You will be given a sedative, propofol, by our anesthesia team who will be present to monitor your vital signs during the examination.
You will most likely begin by lying on your left side. After you receive sedatives, your endoscopist will pass the ultrasound endoscope through your mouth, esophagus and stomach into the duodenum. The instrument does not interfere with your ability to breathe. The actual examination generally takes 30 to 60 minutes. Many do not recall the procedure.
For an EUS examination of the lower gastrointestinal tract, you will start by lying on your left side with your back toward the doctor. Most EUS examinations of the rectum generally take less than 30 minutes.
You should know that if a needle biopsy of a lesion or drainage of a cyst is performed during the EUS, then the procedure will be longer and may take up to one hour.
What happens after EUS?
You will be monitored until most of the effects of the medication have worn off. Your throat might be a little sore, and you might feel bloated because of air introduced into your stomach during the test. You will be given a liquid to drink before you leave. Once you leave, you will be able to eat unless you are instructed otherwise.
The results of the examination will be discussed with you. If a needle biopsy was performed, the material is sent to a pathology lab and the results are available in approximately 10 business days. Your results will be given to you directly at a follow-up appointment or you will receive a letter via standard mail delivery with the results and recommendations for follow-up. All of the results, including your pathology results and procedure reports will be forwarded to your primary care physician and the physician that referred you.
You will not be allowed to drive for 12 hours. You will need to arrange for someone to accompany you home because the sedatives might affect your judgment and reflexes for the rest of the day.
What are the possible complications of EUS?
Although complications can occur, they are rare when doctors with specialized training and experience perform the EUS examination. Bleeding might occur at a biopsy site, but is usually minimal and rarely requires follow-up. You might have a slight sore throat for a day or so.
Other potential but uncommon risks of EUS include a reaction to the sedatives used, aspiration of stomach contents into your lungs, infection, and complications from heart or lung disease. One major but very uncommon complication of EUS is perforation. This is a tear through the lining of the intestine that might require surgery to repair.
The possibility of complications increases slightly if a needle biopsy is performed during the EUS examination, including an increased risk of pancreatitis or infection. These risks must be balanced against the potential benefits of the procedure and the risks of alternative approaches to the condition.